Screening for a Novel Gene, OsPSLSq6, Using QTL Analysis for Lodging Resistance in Rice

Lodging is the most common factor that affects crop productivity, reducing yield, grain quality, and harvesting efficiency of rice and other cereal crops. The Cheongcheong (Indica)/Nagdong (Japonica) doubled haploid (CNDH) genetic map was used to develop a lodging-resistant variety. The major agricultural traits of rice related to lodging resistance, such as the pushing strength of the lower stem before the heading date (PSLSB) at reproductive growth period and pushing strength of the lower stem after the heading date (PSLSA) at full ripe period were investigated. A quantitative trait locus (QTL) analysis of PSLSA and PSLSB detected on RM439-RM20318 on chromosome 6 has overlap in three consecutive years. RM439-RM20318 on chromosome 6 contained 15 lodging resistance candidate genes. Among the candidate genes, Os06g0623200, named OsPSLSq6, which is similar to Cinnamoyl-CoA reductase, involved lignin biosynthesis in defense responses. Lignin is the main structural component of vascular plants’ secondary cell wall, which is not only related to plant growth and development but also to mechanical strength. OsPSLSq6 opens new possibilities to control lignin synthesis to improve lodging resistance. OsPSLSq6 can be used as a target gene for further studies to provide important information for the marker-assisted improvement of target traits and cloning genes underlying the QTL of interest.